Nut and bolt structure



June 2, 1925. 1,540,055

H. J. CHILTON NUT AND am swnuc'ruxin Filed Sept. 5. 1922 INVENTOR ATTORNEY Patented June 2, 1925.

UNITED STATES HENRY.J. CHILTON, OF CHICAGO, ILLINOIS NUT AND BOLT STRUCTURE.

Application filed September To all whom it may concern:

Be it known that I, HENRY J. CHILTON, a citizen of the United States, residing at Chicago, in the county of Cook and State of Illinois, have invented a certain new and useful Improvement in Nut and Bolt Structures, of which the following is a full, clear, concise, and exact description, reference being had to the accompanying drawings, forming a part of this specification.

This invention relates to nut and bolt structures of the well-known and extensively used type employing a castle nut with a cotter pin lying in the slots of the nut and passed through a transverse hole in the bolt to lock the nut on the bolt in various adjusted positions.

The main purpose of the invention, briefly stated, is to provide a construction of this type which shall effect a substantial economy of material in both the bolt and nut and particularly the latter, and a consequent reduction in the cost of production as compared with the standard constructions now known and used, without any sacriflce'of the strength of the nut to resist rupture of the wall thereof.

In the manufacture of castle nuts which are used with a cotter-pin passed through a transverse hole in the bolt and are capable of a limited degree of adjustment lengthwise of the latter while preserving the locking feature, it has heretofore been the universal practice to add to all standard sizes of nuts an integral circular wall or flange on the outer face of the nut and to slot this wall or flange in planes which bisect the wall of the nut midway between the corners of the polygonal periphery which are the thinnest, and consequently the Weakest, regions of the wall. I have discovered that this circular wall or flange, as an addition to the standard nut itself, may be wholly dispensed with, and a nut ofequal strength to resist rupture produced by slotting the face of a standard nut in planes which bisect the wall of the nut at the corners of the polygonal periphery, which are the thickest, and consequently the strongest, regions of the wall and to a depth sufficient to affordthe usual adjustments of the nut lengthwise of the bolt and the locking of the same by the cotterpin; which slotted portion. may also be turned down' to the depth of the slots to provide a circular wall or flange corre- 5, 1922. Serial N6. 586,087.

sponding in form to that of the standard vcastle nut, and to permit the use of the standard length of cotter-pin,'without any sacrifice of strength.

Just as a chain is no stronger than its seating its thickest region or regions, which are at the corners, I have'found that the slots may be made of ample depth to re ceive the cotter-pin wit capacity for the usual degree of adjustment, and still leave at these points transverse wall areas no smaller, and consequently no weaker, than I v the transverse areas extending 'the full length or depth of the nut at the thinnest portions of the wall, and it is this that enables the production of a castle nut of considerably less length or depth than the 7 standard castle nut, and a corresponding reduction in the amount of stock used, without any sacrifice of strength.

In'order that my invention and its inherent advantages and economies, may be better understood by persons skilled in the art I have illustrated the same in the accompanying drawings in which 1 Fig. l is a front elevation of a bolt, castle nut, and cotter-pin embodying the principle of my invention; V

Fig; 2 is a side elevation of the same, in axial section through the nut and a portion of the bolt, with the cotter-pin omitted.

Fig. 3 is asectionof the nut taken on the line 13-13 of Fig. 1; and

Figs. 4 and 5 are views showing the developed areas of the threads of the nut and corresponding threads of. the bolt engaged by the nut.

Referring to the drawings, 10 designates a nut which may be assumed to be a nut of any standard size. Across one face of this nut are formed radial slots 11, 12, 13, 14:, 15 and 16, and it will be observed that these slots extend through those portions of the wall of the nut which are of maximum thickness; that is, the longitudinal planes through the transverse centers ofthe slot bisect t khe -corners of the periphery of the nut. It will further be noted that, in the construction shown, the bottom walls of the slots are concave and substantially semicircular in cross-section, the purpose of which will be hereinafter disclosed.

21 designates the bolt, in usual form ex: cept that my invention enables the same to be made somewhat shorter than when employed with a standard castle nut. In the bolt is formed the usual transverse hole to receive the cotter-pin 2.2 that also engages diametrically opposed slots of the nut; the slots being of considerably greater depth than the diameter of the hole 20 to afford the usnal degree of adjustment of the nut lengthwise ol'the bolt while preserving the locking co-operation of the "cotter-pin and nu t and bolt.

reference to Fig. 3 it will be observed that the area of the radial cross-section through the unslotted portion of the corner of the nut, shown, on the left side of the figure, is no less than, preferably substantialjly equal to, that of a radial cross- I sectionthrough the wall of the nut between thebore" and a point in the periphery midway between adjacentcorners, sho-wn at the right of the "figure; Moreover, since, if the bottoms ofthe slots were flat, the former cross-section wouldgradually decrease in area from the center to the sides of the slot onaccount of the gradual rednction, in the thickness of the wall at these points, I preferably form the slots with rounded concave bottom walls, whereby the gradual reduction in thickness is compensated a cor;- responding increase in height between the planes of: the center and side. walls of. the slotfso that the cross-sectional area of the unslotted portion is substantially constant throughout the full width of the slots; and this, as previously stated, is substantially equal to thecross-sect iQnM area of the wall in a radial plane midway between adjacent corners; It is further noted; that the walls of the nut are so thin (to avoid unnecessary thickness in relation to the bolt) that the last -named cross-section "is of insufficient area andcohesive strength in relationto the diameter of the bore of the nut, 01' :of the diameter of the bolt which it engages, to permit or reduction by slotting. I

" The slotted portion of the nut may be turned down, as shown, to form a usual cir cular flange corresponding to the added flange ofthe standard castle nut, whereby my improved castle nut does not require any greater length of cotter-pin than the standard castle nut; and manifestly this does not reduce the cross-sectional areas above-referred to and consequently does not reduce the strength of the nut to resistrupme: i

reference to Figs, 4 and 5'whic'h illustrate developed thread portions of the nut and corresponding thread portions of the bolt engaged therewith, it will be seen that the. area at the base of the threads of the nut as shown in 4 is substantiallyequal to the shearing area at the base of the threads of the bolt, and thus'the provision of the slots in the nut does not reduce the shear resistingstrength of the structure which manifestly is no greater than the shear resisting strength of that portion of the threads of the bolt engaged by the nut.

I claim and desire to cover by Letters Pate cut is: a r

'1. The combination with a bolt formed with a transverse hole, of a polygonal nut iorinjed with radial slots in one face thereof intersecting the corners of the periphery, and a; c'otter pin engaged withsaid slots and hole, said slots being of a depth suchthat a radial 'crossesection through the unslotted portinn of a corner of the nut is substantially equal in area to a radial' cross-sectihn through thewall ofthe nut between the bore and a point in the periphery midway between adjacent corners. I I

The combination with a bolt formed with a transverse hole, of a polygonalnut formed with radial slots in one face thereof intersecting the corners of the periphery, and a cotter pin engaged with said slots and hole said slots having a uniform depth such that the unslotted portion of a'corne'r has a strength not less than that of the weakest cross-section of thewall of the nut.

'3, The combination with a' bolt fonned with a transverse hole, of a' polygonal nut and a point in; the periphery midway between adjacent, corners; the slo'tte'd portion ofgsairlnut being turned down to thetorm of a circular flange of: uniform thickness equalto the thickness of the wall of the nut midway between adjacent corners.

' L A polygonal nut formed; with radial slots across one face thereof intersecting the corners of the periphery and adapted to be engaged by a ootter pin, said slots being of uniform depth from end to end, said depth being greater than the diameter of the cotter-pin and such that a radial cross-section through the unslotted portion of a corner is at least equal to a radial cross-section through the wall of the nut between the bore and a point in the periphery midway between adjaoent corners. e

5. A polygonal nut formed with radial slots across one face thereof intersecting the corners of the periphery and adapted to be engaged by a cotter-pin, said slots having transversely conoaved bottoms and being of uniform depth from end to end, said depth being greater than the diameter of the cotter-pin and such that a cross-section through the unslotted portion of a corner at any point between the planes of the side walls of the slot is at least equal in area to a radial cross-section through the wall of the nut between adjacent corners, whereby the wall of the nut possesses approximately uniform cohesive strength at all cross-sectional points thereof.

6. A polygonal not having radial slots cut through the corners thereof to such a depth that a cross-section through the remaining unslotted portions of opposite oorners is at least equal in area to a cross-section through the thinnest portions of opposite walls; said last-named cross-section being of insufficient area in relation to the diameter of the bore of the nut to permit of reduction by slotting.

In witness whereof, I hereunto subscribe my name this 2nd day of September A. D., 1922.

HENRY J. CHILTON. 

